<input type="text" name="captcha" class="form-control" style="width: 300px;">
<a onclick="javascript:re_captcha();"  style="cursor: pointer;width: 100px;height: 40px;display: block">
    <img src="{{ url('kit/captcha/1') }}"
         alt="验证码" title="刷新图片" width="100%" height="100%"
         id="c2c98f0de5a04167a9e427d883690ff6" border="0">
</a>
<script>
    function re_captcha() {
        $url = "{{ url('kit/captcha') }}";
        $url = $url + "/" + Math.random();
        document.getElementById('c2c98f0de5a04167a9e427d883690ff6').src=$url;
    }
</script>